Diagnostic Aids
The AIR vacuum bleed system contains a one-way check valve. If system checks out okay, ensure valve is not stuck closed, restricted or blocked. The check valve is located in-line with hose going to vacuum bleed valve.
Using FREEZE FRAME and/or FAILURE RECORDS data mode may aid in locating an intermittent condition. If DTC cannot be duplicated, information included in the FREEZE FRAME and/or FAILURE RECORDS data can be useful in determining how many miles since the DTC set. The FAIL COUNTER and PASS COUNTER can also be used to determine how many ignition cycles the diagnostic reported a pass or a fail condition. To isolate when DTC failed, operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.).